Wireless communication apparatus for rf charging enclosures

ABSTRACT

A RF wireless charging enclosure configured to enable efficient wireless charging of a CE device in the enclosure while also allowing wireless communication of the CE device to devices outside the enclosure. In one example, time multiplexing is used such that the CE device is enabled to either be charged, or to communicate with a device outside the enclosure. In another example, frequency division is used such that the CE device is charged at a first frequency, and simultaneously communicates through the enclosure at a second different frequency.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a Continuation of U.S. application Ser. No.16/999,175 filed on Aug. 21, 2020, and claims priority to U.S.Provisional Application Ser. No. 62/900,953 filed on Sep. 16, 2019, thecontents of which are incorporated fully herein by reference.

TECHNICAL FIELD

The present subject matter relates to wireless charging, e.g., RF powerchargers.

BACKGROUND

Wireless power transfer based on microwave coupling is gainingpopularity in the consumer electronics marketplace as a step of movingaway from the inductively coupled wireless and traditional cabledsolutions. These systems rely on the high frequency (e.g., f_(c)>300MHz) electromagnetic coupling to provide power transfer between tworesonant antennas, one of which is a transmitter and the other one is areceiver.

BRIEF DESCRIPTION OF THE DRAWINGS

The drawing figures depict one or more implementations, by way ofexample only, not by way of limitations. In the figures, like referencenumerals refer to the same or similar elements.

FIG. 1 is a block diagram of a RF charging enclosure having anelectronic door;

FIG. 2 is a block diagram of a RF charging enclosure having anelectronic switch;

FIG. 3 illustrates a CE device prevented from communicating with adevice outside the enclosure when the switch is off;

FIG. 4 illustrates a CE device allowed to communicate with a deviceoutside the enclosure when the switch is on;

FIG. 5 illustrates the enclosure having a lid and a sensor configured todetermine when the lid is closed;

FIG. 6 illustrates a method of charging a CE device in the enclosure;

FIG. 7 illustrates frequency diplexing wherein the CE device can becharged at a first frequency and simultaneously communicate at adifferent second frequency; and

FIG. 8 illustrate frequency diplexing at the front end of a CE device.

DETAILED DESCRIPTION

An RF wireless charging enclosure is configured to enable efficientwireless charging of a consumer electronic (CE) device in the enclosurewhile also allowing wireless communication of the CE device to devicesoutside the enclosure. In one example, time multiplexing is used suchthat the CE device is enabled to either be charged, or to communicatewith a device outside the conductive enclosure. In another example,frequency division is used such that the CE device is charged at a firstfrequency, and simultaneously communicates through the enclosure at asecond different frequency.

Additional objects, advantages and novel features of the examples willbe set forth in part in the description which follows, and in part willbecome apparent to those skilled in the art upon examination of thefollowing and the accompanying drawings or may be learned by productionor operation of the examples. The objects and advantages of the presentsubject matter may be realized and attained by means of themethodologies, instrumentalities and combinations particularly pointedout in the appended claims.

In the following detailed description, numerous specific details are setforth by way of examples in order to provide a thorough understanding ofthe relevant teachings. However, it should be apparent to those skilledin the art that the present teachings may be practiced without suchdetails. In other instances, well known methods, procedures, components,and circuitry have been described at a relatively high-level, withoutdetail, in order to avoid unnecessarily obscuring aspects of the presentteachings.

The term “coupled” as used herein refers to any logical, optical,physical or electrical connection, link or the like by which signals orlight produced or supplied by one system element are imparted to anothercoupled element. Unless described otherwise, coupled elements or devicesare not necessarily directly connected to one another and may beseparated by intermediate components, elements or communication mediathat may modify, manipulate or carry the light or signals.

Reference now is made in detail to the examples illustrated in theaccompanying drawings and discussed below.

Presently, a significant portion of the CE devices run on rechargeablebatteries that are typically reenergized via cable-based chargingsolutions. However, there is a growing interest in eliminating thephysical connections needed for these ubiquitous cable-based chargingsolutions since they limit the flexibility of the design and introducecomplications to the mechanical integrity of the CE device. Thetechnology trend is to replace these cable-based charging solutions withwireless charging systems.

Wireless power transfer based on inductive coupling is gainingpopularity in the consumer electronics marketplace as a concrete step ofmoving away from the cabled solutions. These systems rely on lowfrequency electromagnetic coupling to provide power transfer between twoplanar coils, one of which is a transmitter and the other one is areceiver. This charging scheme is a limited solution as the userexperience can be frustrating due to the stringent alignment and spacingrequirements between the transmitter and receiver coils. Additionally,high permeability ferrite sheets used for inductive charging addsthickness and weight to the end device.

A radio frequency (RF) wireless charging solution that is efficientaddresses both of these concerns. Since many modern CE devices have RFwireless radios in them, some of the wireless infrastructure can bereused (such as the antenna) and thus eliminate some of the weight andspace concerns. The inherent nature of RF near field coupling allowssignificant versatility improvement over inductive charging in how thereceiver is placed with respect to the wireless power transmitter. Adrawback with this versatility is the lost power transmission efficiencyif the receiver and the transmitter are not in a shielded environment,as some of the RF energy sent by the transmitter radiates away from theintended target. Companies have introduced carefully designed cavitiesand faraday cages that keep the entirety of the transmitted energyinside the enclosure which allows the receiver to capture RF energy withmaximum efficiency.

In one example, a wireless charging system includes a metal enclosurehaving a metal lid and an embedded transmitter. The system becomesoperational when the metal lid is closed. The closed off enclosureensures that the energy sent by the transmitter has nowhere to go but toa receiver of a CE device placed in the enclosure, which in turn usesthat power to energize the rechargeable batteries. This efficiencyimprovement comes at a cost, in that, now the receiving CE device isinside a metal enclosure and has no wireless access to the outside worldduring charging.

This disclosure includes a RF wireless charging enclosure configured toenable efficient wireless charging of a CE device while also allowingwireless communication of the CE device to devices outside theenclosure.

In order for the receiving CE device to communicate with the outsideworld while in a confined metal enclosure, such as copper in oneexample, physical openings are formed in the walls of the enclosure.These physical openings will result in energy leakage if they are toobig when RF wireless charging is happening. If the openings are toosmall, then the wireless communication of the CE device with theexternal world will be severely impaired. As such, a physical opening isneeded that is big enough when the CE device is communicating, and assmall as possible when wirelessly charging the CE device. In simpleterms, an electronic switchable door on the metal enclosure enables suchbehavior as shown in FIG. 1 .

In the example shown in FIG. 1 , an RF charging system 10 istime-duplexed, in that an electronically switchable door 12 of enclosure14 is closed when an RF charger transmitter 16 is wirelessly chargingthe CE device 18, and then opened when the CE device 18 needs tocommunicate with the outer world, such as with a wireless local areanetwork/wireless wide area network (WLAN/WWAN) access point 20. In oneexample, this electronic door 12 is opened and closed withinmilliseconds for a modern time duplexing system to be functional.

FIG. 2 illustrates an electronic switch operating as the switchable door12 to provide time duplexed charging and wireless communication. Whenthe wireless charging of CE device 18 is occurring using transmitterantenna 21 and CE device antenna 23, the electronic switch 12disconnects an antenna 22 inside the enclosure 14 from an antenna 24 onthe outside of the enclosure 12. This switch 12 ensures that the RFenergy leakage from the enclosure 14 during charging is minimized as thecharging energy has nowhere to go from the transmitter 16 but to the CEdevice 18. When it is time for the CE device 18 to communicate with theouter world, and the transmitter 16 is not enabled, this electronicswitch 12 connects the two antennas 22 and 24 to provide a reliable RFlink between an antenna 23 of the CE device 18 and the WLAN/WWAN accesspoint 20. In one example, the RF charger transmitter 16 sends a controlsignal on control line 28 that controls the connection of the antennas22 and 24 such that they are disconnected when the RF chargertransmitter 16 is transmitting RF power, and connected when the RFcharger transmitter 16 is off. The antennas 22 and 24 of the electronicswitch 12 are designed with consideration of the electromagneticproperties of the enclosure cavity 30 and are properly matched withrespect to their electrical impedance. The antennas 22 and 24 arepassive, and are operatively connected to each other when thetransmitter 16 is not active and not charging the CE device 18. Theantennas 22 and 24 could be high bandwidth patch type antennas that aretuned to operate inside the cavity and in the free space, respectively.Antennas 22 and 24 are not necessarily designed to be 50 ohms butdesigned to the impedance that allows maximum energy extraction from theenclosure cavity when connected.

As seen in FIG. 3 , when the electronic switch 12 is off duringcharging, there is no communication between the antenna 22 on the insideof the enclosure 14 and the antenna 24 on the outside of the enclosure.Thus, the CE device 18 cannot communicate with the WLAN/WWAN accesspoint 20. The RF charging energy is contained inside the wirelesscharging enclosure 14.

However, as shown in FIG. 4 , when the electronic switch 12 opens, suchas when the RF charger transmitter 16 is off, the antenna 24 on theperimeter of the enclosure 14 is connected with the antenna 22 inside ofthe enclosure. Now, the CE device 18 can wirelessly communicate withWLAN/WWAN access point 20 via antenna 22 and antenna 24.

There are multiple methods to implement the time-duplexed chargingscheme described. FIG. 5 and FIG. 6 illustrate one example, where anenclosure switch 40 extending upwardly on the upper rim 42 of theenclosure 14 is compressed and closed when a metal enclosure lid 44 isclosed. Once the transmitter 16 detects that the switch 40 is closed,the transmitter 16 will control the electronic switch 12 to go to itsdefault position, the off state, where RF communication between insidethe enclosure 14 and outside the enclosure 14 is not allowed.

Referring to the method 60 shown in FIG. 6 , at block 62 the lid 44closed by a user to enclose the CE device 18 in the enclosure.

At block 64, the RF transmitter 16 detects if a CE device 18 is presentin the enclosure 14. In one example, the RF transmitter 16 sends a lowamplitude RF charge signal for a certain amount of time via antenna 21,for example 2 seconds, and then moves on to its listening mode. If theRF transmitter 16 does not get a response back from the CE device 18 inthe listening mode, this means there is no CE device 18 present and theRF transmitter 16 will shut off until the next lid closure event. In themeantime, the CE device 18 frequently checks if there is a chargingsignal coming in as it has a logic that allows it to switch its antenna23 between its RF radio and RF charger. The switching frequency shouldbe less than the wait time of the RF transmitter 16, in this example 2seconds.

At step 66, once the CE device 18 detects that it is in a chargingenvironment, as it received the low amplitude charging signal from thetransmitter 16 via antenna 23, it replies back and tells the RFtransmitter 16 its state of battery charge and the temperature of itscritical components over an RF link 46. This RF link 46 can be a simplemodulation scheme with no security (as simple as amplitude modulation)as this communication is completely isolated from the outside world.

At block 68, the RF transmitter 16 and the CE device 18 are now incharging mode, and sync their clocks using RF link 46 and agree to RFcharge for a certain amount of time and amplitude (say 3 seconds, maxamplitude in this example) depending on the state of battery charge andthe temperature of the CE device 18 critical components. Switch 12 isoff which prevents communication of the RF charge signal from emanatingfrom the enclosure 12 via switch 12.

At block 70, after this set amount of time expires (3 seconds in thisexample), the RF transmitter 16 switches to listen mode to check in withthe CE device 18. The goal is to inquire about state of CE device 18battery charge, temperature, and if there is a desire to communicatewith the outer world. If CE device 18 needs more charging and no desireto communicate with the outer world, the process repeats itself withmore RF charging.

At block 72, if the CE device 18 does not need charging anymore, the RFtransmitter 16 turns off until the next lid event and informs theelectronic switch 12 via control line 28 to go to the “on” state. If CEdevice 18 needs to communicate with the outer world, the RF transmitter16 informs the electronic switch 12 that CE device 18 wants tocommunicate with the outer world and goes to listening mode. Electronicswitch 12 then goes to the “on” position and connects the two antennas22 and 24 to provide a link between outer world and the CE device 18.

Once CE device 18 is done communicating with the outer world, it sendsthe state of its battery charge and the temperature of its criticalcomponents over the same simple RF link 46 to the RF transmitter 16. RFtransmitter 16 was already in the listening mode waiting to be informedif a charging event is needed. Thus, when the charging request comes in,RF transmitter 16 relays to the electronic switch 12 that a chargingprocess is about to start. Electronic switch 12 returns to its offposition and RF transmitter 16 again sends an RF charge for that fixedcertain amount of time, which was 3 seconds in this example. The processrepeats itself as it is negotiated between the RF transmitter 16 and theCE device 18.

In another example, as shown in FIG. 7 , frequency duplexing is utilizedwhere the RF charging of CE device 18 is performed using a firstfrequency f1, and a second different frequency f2 is used for CE device18 communication. As an example, the RF transmitter 16 performs RFcharging at 915 MHz, while the CE device 18 communication operates using2.4 GHz or 5.2 GHz ISM bands.

As shown in FIG. 7 , the CE device 18 communication is done using CEdevice antenna 23 and antennas 22/24, and RF charging is simultaneouslydone using a transmitter antenna 21 and a second CE device antenna 25.The electronic switch antennas 22 and 24 are designed to ensure that theRF energy at frequency f1 coming from the RF charger transmitter 16cannot escape the enclosure 14, while CE device 18 communication atfrequency f2 can occur simultaneously. The switch 12 has a bandpassfilter with high rejection to allow for wireless communicationfrequencies f2 to go through the switch 12 from CE device 18 toWLAN/WWAN access point 20, and which bandpass filter blocks the RFcharging frequency signals.

Alternatively, the CE device 18 antennas can be combined as a singleantenna 23 that has multi-band radiation characteristics. In thisscenario, as illustrated in FIG. 8 , the CE device 18 utilizes afrequency diplexer 82 in its RF front end to separate the RF chargeenergy from the RF communication energy in spectral domain. A diplexeris configured to separate frequency bands. A bandpass filter 84 onlypermits communication of the higher frequency f2 between a RF front end86 for CE device and antenna 23, and a bandpass filter 88 only permitscommunication of the RF charging signal at the lower frequency f1 fromantenna 23 and RF charging circuitry 90 of the CE device 18.

It will be understood that the terms and expressions used herein havethe ordinary meaning as is accorded to such terms and expressions withrespect to their corresponding respective areas of inquiry and studyexcept where specific meanings have otherwise been set forth herein.Relational terms such as first and second and the like may be usedsolely to distinguish one entity or action from another withoutnecessarily requiring or implying any actual such relationship or orderbetween such entities or actions. The terms “comprises,” “comprising,”“includes,” “including,” or any other variation thereof, are intended tocover a non-exclusive inclusion, such that a process, method, article,or apparatus that comprises or includes a list of elements or steps doesnot include only those elements or steps but may include other elementsor steps not expressly listed or inherent to such process, method,article, or apparatus. An element preceded by “a” or “an” does not,without further constraints, preclude the existence of additionalidentical elements in the process, method, article, or apparatus thatcomprises the element.

Unless otherwise stated, any and all measurements, values, ratings,positions, magnitudes, sizes, and other specifications that are setforth in this specification, including in the claims that follow, areapproximate, not exact. Such amounts are intended to have a reasonablerange that is consistent with the functions to which they relate andwith what is customary in the art to which they pertain. For example,unless expressly stated otherwise, a parameter value or the like mayvary by as much as ±10% from the stated amount.

In addition, in the foregoing Detailed Description, it can be seen thatvarious features are grouped together in various examples for thepurpose of streamlining the disclosure. This method of disclosure is notto be interpreted as reflecting an intention that the claimed examplesrequire more features than are expressly recited in each claim. Rather,as the following claims reflect, the subject matter to be protected liesin less than all features of any single disclosed example. Thus, thefollowing claims are hereby incorporated into the Detailed Description,with each claim standing on its own as a separately claimed subjectmatter.

While the foregoing has described what are considered to be the bestmode and other examples, it is understood that various modifications maybe made therein and that the subject matter disclosed herein may beimplemented in various forms and examples, and that they may be appliedin numerous applications, only some of which have been described herein.It is intended by the following claims to claim any and allmodifications and variations that fall within the true scope of thepresent concepts.

1.-20. (canceled)
 21. A charger, comprising: an enclosure at leastpartially encompassing a cavity; a RF transmitter configured to generatean RF charge signal within the cavity, the RF charge signal configuredto wirelessly charge a device within the cavity; and a switchableantenna coupled to the enclosure and configured to selectively pass anRF communication signal through the enclosure.
 22. The charger of claim21, wherein the switchable antenna is configured to selectively pass theRF communication signal through the enclosure as a function of atransmission state of the RF transmitter.
 23. The charger of claim 21,wherein the RF transmitter is configured to generate the RF chargesignal and control the switchable antenna to prevent communication ofthe RF communication signal through the switchable antenna in a firstmode, and wherein the RF transmitter is configured to not generate theRF charge signal and control the switchable antenna to permitcommunication of the RF communication signal through the switchableantenna in a second mode.
 24. The charger of claim 21, wherein the RFcharge signal has a first frequency and the RF communication signal hasa different second frequency.
 25. The charger of claim 21, wherein theswitchable antenna extends through a wall of the enclosure.
 26. Thecharger of claim 25, wherein the switchable antenna comprises a firstantenna and a second antenna.
 27. The charger of claim 26, wherein thefirst antenna is exposed to the cavity and the second antenna is exposedto outside the enclosure.
 28. The charger of claim 26, wherein the firstantenna and the second antenna are impedance matched and configured tobe selectively coupled to each other.
 29. The charger of claim 26,wherein the first antenna and the second antenna are passive.
 30. Thecharger of claim 21, wherein the enclosure includes a lid and a switchconfigured to detect when the lid is closed, wherein the RF transmitteris configured to generate the RF charge signal when the lid is closed.31. A system, comprising: a device configured to generate an RFcommunication signal; an enclosure at least partially encompassing acavity receiving the device; a RF transmitter configured to generate anRF charge signal within the cavity, the RF charge signal configured towirelessly charge the device within the cavity; and a switchable antennacoupled to the enclosure and configured to selectively pass the RFcommunication signal from the device through the enclosure.
 32. A methodof RF charging a device in a charger, comprising an enclosure at leastpartially encompassing a cavity, a RF transmitter configured to generatean RF charge signal within the cavity, the RF charge signal configuredto wirelessly charge a device within the cavity, and a switchableantenna coupled to the enclosure and configured to selectively pass anRF communication signal through the enclosure, comprising the steps of:selectively allowing communication of the RF communication signalthrough the switchable antenna during a first time period; and RFcharging the device in the enclosure during a second time period that isdifferent than the first time period.
 33. The method of claim 32,wherein the switchable antenna selectively passes the RF communicationsignal through the enclosure as a function of a transmission state ofthe RF transmitter.
 34. The method of claim 32, wherein the RFtransmitter generates the RF charge signal and controls the switchableantenna to prevent communication of the RF communication signal throughthe switchable antenna in a first mode, and wherein the RF transmitterdoes not generate the RF charge signal and controls the switchableantenna to permit communication of the RF communication signal throughthe switchable antenna in a second mode.
 35. The method of claim 32,wherein the RF charge signal has a first frequency and the RFcommunication signal has a different second frequency
 36. The method ofclaim 32, wherein the switchable antenna extends through a wall of theenclosure.
 37. The method of claim 36, wherein the switchable antennacomprises a first antenna and a second antenna selectively coupled toeach other.
 38. The method of claim 37, wherein the first antenna isexposed to the cavity and the second antenna is exposed to outside theenclosure.
 39. The method of claim 32, wherein the enclosure includes alid and a switch detecting when the lid is closed, further comprising:detecting when the lid is closed; determining if the device is in thecavity when the lid is closed; and RF charging the device when thedevice is detected in the cavity.
 40. The method of claim 39, whereinthe device is determined to be in the cavity by the RF transmittersending the charge signal for a predetermined time period and receivinga response signal within another predetermined time period.